Razor stropper



Aug. 9, 1932. F. H. BORM v RAZOR STROPPEH Filed June s, 192@ 2 Sheets-Sheet l F. H. BQRM RAZOR STROPPER Aug. 9, 1932.

Filed June 8, 1928 I 2 Sheets-Sheet 2 lhvenbr. Irdzfzand H. Barni His Aiorney.

Patented Aug. 9, 1932 STATES RAZOR STROPPER Original application filed December 10, 1926, Serial No. 153,740. Divided and thisV application filed June 8, 1928. Serial No. 283,786.

This invention relates to improvements in abrading mechanism, and more particularly to an improved rotatable drum provided with an abrading surface for sharpening razor blades.

A further object of the invention is .the effective sharpening of razor blades without injury, regardless of variations and irregu larities such as usually exist incident to slight deflections or out-of-alignment conditions of razor blade edges.

A more specific object is the provision of a device of this character adapted to rectify the misplaced or misaligned teeth or serrations which make up a. razor cutting edge without the danger of breaking olf the teeth, or distorting or otherwise injuring the material of the blade along the line of the serra-- tions.

A. further detailed object is the provision of a burnishing or abrading surface sustained by a comparatively hard and stable sub-support which still possesses the capacity of flexing in all necessary directions suiiiciently to enable all parts of a razor blade edge to find contact with the abrading surfaceiwithout either excessive flexing of the edge of depression thereof into the engaged surface. In other words, the device of the invention comprises the provisions of a burnishing or abrading surface and a support therefor capable of maintaining its normal contour under ordinary stresses, but suliiciently flexible to give under a stress less than that necessary to injuriously iex a portion of the edge of a blade.

The present application constitutes a division of applicants co-pending application, Serial No. 153,740, filed December 10th, 1926.

Other objects will appear hereinafter.

The invention consists in the combinations and arrangements of parts hereinafter described and claimed.

The invention will be best understood by reference to the accompanying drawings forming a part of this specification, and in which:

Figure l is a side elevational view of an abrader drum of the present invention;

Figure 2 is an end elevation of the device shown in Figure l lookin g from the right;

Figure 3 is a perspective view of the inner clamping plate or stabilizer detached;

Figure 4f is a perspective view of the sup porting shell for the abrading material;

Figure 5 is a perspective view of the outer clamping plate for the abrading material;

Figure 6 is a transverse section through a modified form of abrader;

Figure 7 is a side elevation, upon a reduced scale, of the shell portion of the structure shown in Figure 8, the intermediate portion being broken away;

Figure 8 is an enlarged detailed fragmen- 5b tary section of two of the coils forming the shell shown in Figure 7.

Figure 9 is a plan view of a pair of drums of the present invention mounted in a suitable holder with an operating handle provided;

Figure 10 is a transverse section taken on the line lO--lO of Figure l, certain parts being shown in elevation; and

Figure lly is a fragmentary section of the parts shown in Figure 10 illustrating an eX- aggerated distortion of the blade and its effect upon the drum.

It will be understood by those familiar with the art to which the present invention pertains, that edges of edged tools, however fine and perfect, appear uncer a microscope as a line of irregular teeth or serrations separated by fine cracks, and in the forming of fine edges such as required for razor blades and the like, particular care is exercised to utilize material for the edge and to so treat it in the sharpening process as to avoid, as far as possible, any cracking or opening of the material between the teeth. Such cracking largely destroys the support for the teeth, and therefore permits the teeth to more readily bend or otherwise iex permanently out of alignment.

It is understood, of course, that any substantial or permanent deilection of the teeth from alignment results in a dulled edge, and cracks or flaws, though microscopic, increase the ease with which an edge may be dulled.

Excessive or repeated deflecting'of the teeth 10 to a kgreater extent than necessary in an effort to bring them into alignment or otherwise sharpen them, frequently results in crystallization along the line of flexing, and the teeth break off leaving a nicked edge, It frequently occurs in the formation of edged tools, especially razor blades, that the degree of precision in the approximation of the edge to a straight line is not very high. Some blades are flexed toward one end portion, others toward another, and still othersrvmorc or less bowed, or otherwise out of perfect alignment. Such irregularities are usually not great enough to be readily perceived by the naked eye, but when a Vblade is `laid against an abrading or polishing surface, a certain amount of stress must be exerted on one relative to the other to cause all parts of the edge to simultaneously Contact with the surface. If the alignment is sufficiently accurate to enable such contact with sufficiently limited stress on the teeth of the edge, little, if any, harm will result, but beyond a certain point of deflecting to reach contact with the abrading surface, the strain will be sufficiently great to cause or tend to cause excessive and injurious defiction of the teeth at the edge portion where the greatest stress is applied,

' with a result of permanent injury to the blade. It is an important object of the present invention to enable effective sharpening of blades without danger of any such injurious results, and for the purpose of convenience the term abrade will be utilized hereinafter to signify any action destined to or intended for the restoration of a dulled blade to a sharpened condition, it being understood that the term burnishing herein employed is onlyv distinguished in a degree from abrading, and in many instances the Y sharpening is effected without actual abrading or removal of material from the edge of the blade, the sharpening action'in such case comprising merely the restoration of the teeth of the edge to a cleaned and aligned condition. Therefore, in the appended claims, the terminology should be interpreted to include this form of sharpening, even though the term abrade be utilized to describe the actions. In applying an abrading surfacel to a. razor blade edge, it is further- `more highly important to have the yielding action of the surface to compensate for blade irregularities, take place without any change in the angle at which the abrading surface isfdisposed relative to the blade edge. ln the hand 'stropping of razors, which is the most effective and the least injurious to razor blade edges, the foregoing objections to mechanical stroppers are practically eliminated because there is no rigid support beneath the strop and the strop is free to conform to the alignment of the blade edge with the pressure evenly distributed.

Furthermore, when properly used, the

hand strop is held sufficiently taut so that the surface of the strop is disposed at a proper angle relative to the body of the blade so as to procure best results, and only suiicient pressure is exerted to bring the teeth in alignment without unduly deflecting the teeth so as to cause weakening, breakage, or crystallization at the base of the teeth'. It is, therefore, an object of the present invention to duplicate7 as nearly as practicable, the action which takes place in hand stropping by the provision of a mechanical stropper having a flexible drum so constructed as to yield and adapt itself to the contour of a blade edge under pressure less than suflicient to cause injury to the edge.

Referring to the drawings which illustrate ing material 18, preferably of leather, is y stretched upon shell 12 and held in place by upwardly projecting points 19, and also by the two rows of serrations 20 and 21 disposed along the lateral edges of member 17. Plate 17 is provided with openings 22 and 23 which `upon assembly register with similar openings provided upon the inner clamping plate 16 for the reception of suitable securing means, such as tubular rivets 24. Upon each end of the inner clamping plate, tabs 25 are provided and the tabs of each end are adapted to be inserted through slots 26 in a drum end member y27. Each drum end member 27 is provided with a trunnion 28 for pivotally mounting. the drum in the casing 27. It will be noted that the shell 12 is partly cylindrical, that portion carrying the abrading material 18 which is to contact with the blade edge being transversely struck on the arc ofA a circle described from the axis of the drum as its center. It will be readily understood that the shell 12 being made of thin brass or other suitable material affording stabilizing fiexibility,

the results-sought would be largely negatived if the ends of that portion of the shell which supports the edge contacting abrading material were rigidly held against flexing. Hence, in making up the drum, those parts of the end portions which are liable to require flexing are not anchored to the drum heads 27 but are left free to flex. Tabs 25 are clinched upon assembly with the drum ends as shown in Figure 2, and each drum is provided with a gear 29 adapted to mesh kwith. a geary on a duplicate drum so as to bring the two drums within the casing 27 in the relative positions shown in Figure 10, wherein the engagement of the abrading surfaces with the blade edge alternates. A suitable mounting for the entire assembled device is shown in Figure 10 wherein the blade 29 is held in position by means of a clamp 30 and as shown in Figure 9 a handle 31 projects from the end of one drum for imparting rotative motion. In Figure 11 there is illustrated an exaggerated distortion of the blade 29 requiring flexing of the shell 12. The exaggeration is necessary for the purpose of clear illustration since the usual extent of flexing is ordinarily so slight as to be diflicult of observation by the naked eye, and it is to be particularly noted that there is no indentation or depression of the abrading material immediately adjacent the blade edge but that the entire shell and necessarily the supported abrading material is displaced in such manner that the angle of contact with the blade edge is unchanged. The importance of this is that the edge serrations or teeth are not unduly bent at the line of junction with the body of the blade. As a further means of obtaining this result, as shown in Figure 10, the lateral edges 32 of the angularly disposed portions of the inner clamping plate 16 are preferably turned in'- wardly toward the center of the drum so as to avoid any rigid support for the shell 12 at a. point where the blade edge contacts with the abrading surface, and thus it will be seen that shell 12 and the abrading material Y18 are anchored and secured at points remote from the blade edge engaging area. No condition of any average blade will be such as to cause the edge portion thereof to enter or imbed itself in the abrading surface to such an extent as to cause injury to the blade edge because of the relative resistant character of the sub-support provided by the shell 12.

In Figures 6 and 'r' are illustrated a modified embodiment relating more particularly to the construction of the supporting shell.

In this embodiment the shell 12 is formed from a coil spring each helix preferably being fiat to provide the requisite smooth surface of the finished drum. as shown in Figure 8. Mounted upon the shell 12isthe abrading material 18 and the shell and the abrading material are clamped by plates 16 and 17", and the parts are otherwise constructed as to the manner above described with respect to the form and details of the abrading drum.

It will be apparent from the foregoing that the invention is characterized in that by the use of an embodiment thereof a blade may be sharpened without injury, and by injury is included weakening, crystallization or permanent deflecting of any portions of the blade edge, all of which factors contribute to prevent proper sharpening either by causing breakage of the teeth or misalignment.

While I have illustrated and described the preferred form of construction for carrying my invention into efl'ect this is capable of variation and modification without departing from the spirit of the invention. I therefore do not wish to be limited to the precise details of construction set forth, but desire to avail myself of such variations and modifications as come within the scope of the appended claims.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A stropping device of the class described comprising a drum member composed of end members and a fiexible shell covered with an abrading material; said flexible shell having a cylindrical portion and a flattened portion and secured to said end members only at points upon said flattened portion to permit longitudinal and transverse flexing of said cylindrical portion.

2. A stropping device of the class described comprising a drum member composed of end members and a flexible shell covered with an abrading material; said exible shell having a cylindrical portion and a flattened portion and secured to said end members only at points upon said flattened portion to permit longitudinal and transverse flexing of said cylindrical portion, and means for securing said abrading material to said shell at points upon said flattened portion.

3. A stropping roll comprising a drum composed of a flexible cylindrical shell, said shell having a flattened portion, end members for said shell having openings thereon,

stropping material disposed upon said shell; clamping means comprising opposed clamping members, one of said members engaging the inner portion of the shell and the other member engaging the stropping member, lugs on the ends of one of said clamping members adapted to engage the openings in said end members whereby the clamping members, and shell, are secured to said end members.

In testimony whereof, I have signed my name to this specification.

FERDINAND H. BORM. 

